This invention relates to manufacture of, e.g. absorbent, personal care articles, especially to methods and apparatus for assembly of multiple component extensible webs, and personal care articles manufactured from such webs. More specifically, this invention relates to methods and apparatus for assembly of webs, preferably extensible webs, and personal care articles manufactured therefrom wherein the methods and apparatus of the invention diminish inefficient attributes of methods associated with conventional processes for manufacturing personal care articles. While embodiments of the present invention are described herein in terms of personal care articles such as pull-on pants or adult incontinence briefs, the invention includes, and is equally applicable to, infant diapers, training pants, and like personal care articles.
In conventional methods for fabricating personal care absorbent articles, it is known to build workplaces on a uniform, continuous web or webs as the web or webs advance through a series of work stations on a manufacturing line, wherein each work station effects a modification to a web or workpiece element, such as cuts or additions of absorbent article components to such web, webs, or workpiece element. Individual workplaces are then severed from the uniform continuous web or webs to form individual absorbent personal care articles or article blanks. In such conventional methods for fabricating personal care articles, ancillary components, such as fastener tabs and fastening areas or landing zones, are affixed to such articles or article blanks either at the work stations of such manufacturing line or at a subsequent stage in the manufacturing process after separation of such articles or article blanks from the web or webs.
A need exists for improved methods for production of personal care absorbent articles wherein the methods are effective to reduce material waste and to improve time efficiency of the manufacturing process as well as to reduce financial waste inevitably associated with time inefficiency of such manufacturing process. A need exists for improved methods for production of personal care absorbent articles wherein the methods are effective to attenuate material waste and time inefficiency associated with conventional manufacturing processes as well as to reduce the financial burden associated with such inefficiencies and waste.
Thus, it is an object of the invention to provide improved methods for production of personal care absorbent articles which implement a more xe2x80x9cmanufacture-friendlyxe2x80x9d extensible web as a base structure from which to assemble personal care absorbent articles, enabling a manufacturer to assemble such articles while employing relatively fewer work stations on the manufacturing line, compared to conventional methods, thus reducing production time.
It is another object of the invention to provide improved manufacturing methods which include fabricating a web of indefinite length by adding alternating workpieces and intervening elements to the web segment so as to develop a self-supporting web of indefinite length, wherein support of such self-supporting web along the indefinite length of such web is primarily defined by the alternating workpieces and intervening elements making up the web.
It is yet another object of the invention to provide improved manufacturing methods including defining, in the workpieces, mechanical fasteners effective to engage the intervening elements.
It is a further object of the invention to provide improved manufacturing methods wherein the releasable attachment of the workpieces to the intervening elements comprises the only attachment between the workpieces and the intervening elements.
It is a still further object of the invention to provide improved manufacturing methods which reduce the relative quantity of raw material which is wasted in the manufacturing of personal care-type articles.
In a first family of embodiments, the invention comprehends a method of fabricating a web suitable for use in making a personal care absorbent article. The method comprises fabricating a resiliently extensible web by bringing together and securing to each other web substrate elements and resiliently stretchable elastic elements in stretched condition. The securement between the elastic elements and the web substrate elements is defined by alternating zones of securement and non-securement of the elastic elements to at least one of the web substrate elements along a length of the web substrate. The method also includes deactivating elastic elements in the non-securement zones thereby to attenuate resilient retraction of the web in such non-securement zones in response to activity of the elastics, and correspondingly, to distinguish the securement zones as relatively more resiliently stretchable and the non-securement zones as relatively less resiliently stretchable. The method further includes applying, to the relatively non-stretchable non-securement zones, patches of mechanical fastener material extending generally between respective adjacent ones of the relatively more resiliently stretchable securement zones.
In preferred embodiments, the invention comprises fabricating a workpiece suitable for use in a personal care article including defining a first end of such workpiece in the web by defining a free end of the web through a respective patch of the hook fastener material, and separating the workpiece from the web through a second respective patch of the hook fastener material such that hook fastener patch material is defined at opposing end portions of the respective workpiece.
In such preferred embodiments, the invention can comprise fabricating an extensible web from respective ones of first and second workpieces, wherein such web is suitable for use as a substrate in making a personal care article. The method comprises arranging workpieces in generally end-to-end relationship with intervening elements, and releasably attaching the hook material on the workpieces to hook receptive areas on the intervening elements, thus to releasably attach the workpieces to the intervening elements in fabricating a length of the extensible web.
The releasable attachment of the workpieces to the intervening elements comprises the primary structural attachment, and preferably the only attachment, between the workplaces and the intervening elements.
The method can comprise developing an alternating arrangement of the workpieces and the intervening elements such that each such workplace is between two such intervening elements and each such intervening element is between two such workpieces.
In some embodiments, the method comprises arranging workpieces in generally end-to-end relationship with intervening elements, respective ones of the intervening elements having lengths and widths defining respective surface areas, the hook receptive areas of such respective intervening elements generally corresponding to such surface areas. Such method includes releasably attaching the hook material on the workpieces to the intervening elements at the hook receptive areas, thus to releasably attach the workpieces and the intervening elements to each other in fabricating a length of the extensible web.
Methods of the invention typically include deactivating elastic elements in the non-securement zones preferably by cutting such elastic elements or by applying ultrasonic energy to such elastic elements optionally through an intervening layer.
In a second family of embodiments, the invention comprehends a method comprising fabricating a base web comprising multiple workpieces, applying patches of mechanical fastener material to such base web, and defining a first end of such workpiece by defining a free end of the base web through a respective patch of the fastener material, and separating the workpiece from the base web through a second respective patch of the fastener material such that a patch of fastener material is defined at both opposing end portions of the respective workpiece.
In preferred embodiments, the method includes arranging workpieces in generally end-to-end relationship with intervening elements, and releasably attaching the fastener material on the workpieces to fastener receptive areas on the intervening elements, thus to releasably attach the workpieces to the intervening elements in fabricating a length of composite web.
In some embodiments, the fastener material comprises a mechanical hook material.
In preferred embodiments, the intervening elements comprise a material which demonstrates fastener receptive properties, wherein the material of the intervening element is capable of forming engagement relationships with respective fastener materials.
In some embodiments, the method includes affixing the fastener receptive area, as a separate web element, to the intervening element, wherein the fastener receptive area has distinct physical edges.
In other embodiments, the fastener receptive area is integral with a major surface of the intervening element. The fastener receptive area is, thus, void of distinct physical edges.
In preferred embodiments, the base web comprises a neck-bonded laminate or a stretch-bonded laminate.
In a third family of embodiments, the invention comprehends a method of fabricating a self-supporting web of material from respective workpieces and intervening elements, wherein such self-supporting web is suitable for use as a substrate in making a personal care article. The method comprises bringing together an intervening element having first and second ends, a first workpiece having third and fourth ends, and a second workpiece having fifth and sixth ends, with first, second, and third lengths of the respective first and second workpieces and the intervening element aligned with each other in a generally common surface, and with the second and third lengths of the first and second workpieces operating as extensions of the first length of the intervening element, on opposing ones of the first and second ends of the intervening element. The method also includes releasably attaching the first workpiece and the intervening element to each other at the respective first and fourth ends, using releasable fasteners, and releasably attaching the second workpiece and the intervening element to each other at the respective second and fifth ends, using releasable fasteners, such that the first, second, and third lengths, in combination, define a self-supporting web segment having a fourth length. The fourth length of the web segment so defined by the combination of the first, second, and third lengths is greater than any of the first, second, and third lengths, individually, of the respective first and second workpieces and the intervening element. Additional such alternating workpieces and intervening elements can be releasably attached to one or both of the third and sixth ends of the respective first and second workpieces using additional releasable fasteners, to thereby further extend the length of the self-supporting web, wherein the releasable fasteners employed in so assembling the self-supporting web can be released so as to release respective ones of the workpieces and intervening elements of the self-supporting web from each other.
In some embodiments, the second and third lengths of the first and second workpieces are defined at rest, wherein the first and second workpieces are resiliently extensible by at least 100 percent of the respective second and third lengths, the method including attaching the first and second workpieces to the intervening element while the respective first and second workpieces are stretched substantially to stop.
In other embodiments, the method includes attaching the first and second workpieces to the intervening element while the respective first and second workpieces are being subjected to a stretching tension stretching the lengths of the respective first and second workpieces at least 50 percent from the respective second and third lengths.
In yet other embodiments, the first and second workpieces demonstrate effectively no elasticity. In such embodiments, the method involves substantially no stretching of the first and second workpieces, and simply includes attaching the first and second workpieces to the intervening element.
In preferred embodiments, the first and second workpieces are attached to the intervening element by fasteners having attachment capability over a substantial portion of an area defining the intervening element.
The first and second workpieces are preferably attached to the intervening element by first and second attachments defining mechanical fasteners on one of the respective workpieces and/or the intervening element interacting with mechanical loops on the other of the respective workplace and/or the intervening element.
In some embodiments, the method includes fabricating a web of indefinite length by adding alternating workpieces and intervening elements to the web segment so as to develop a self-supporting web of indefinite length wherein support of such self-supporting web along the indefinite length of such web is defined by the alternating workpieces and intervening elements making up the web.
Some embodiments of the method include defining, in the workpieces, mechanical fasteners effective to engage the intervening elements.
In a fourth family of embodiments, the invention comprehends a self-supporting web of sheet material suitable for use in making a personal care article, the self-supporting web comprising a sequence of at least first and second workplaces and intervening elements, including opposing ends on the respective workpieces and intervening elements. The respective workpieces and intervening elements have unstressed lengths between the respective ends thereof, the unstressed lengths of the respective workpieces and intervening elements being aligned with each other in a generally common surface, and operating as extensions of each other, such that the unstressed lengths, in combination, define a length of the web. The workpieces and intervening elements, in combination, generally define self-supporting longitudinal strength of the web. The workpieces and intervening elements are releasably attached to each other, using releasable fasteners, wherein the releasable fasteners employed in so assembling the web can be released so as to release respective ones of the workpieces and intervening elements from the self-supporting web.
In some embodiments, ones of the workpieces can be resiliently extended at least 100 percent from the unstressed lengths of the respective workpieces.
Preferred embodiments include employing hook and loop fastening structure in effecting the releasable fastening of the workpieces and intervening elements.
In a fifth family of embodiments, the invention comprehends a method of fabricating personal care absorbent articles. The method includes advancing along a processing line a first web having a first length. The first web is suitable for use in making a personal care article, and comprises at least workpieces and intervening elements releasably attached to each other using releasable fasteners to thereby define such first web and self-supporting longitudinal strength of such web, whereby such workpieces and intervening elements generally define the structure and the structural integrity of the first web. The method also includes concurrently advancing a second web having a second length along the processing line and generally parallel to the first web, and defining a space between the first and second webs, the second web being suitable for use in making such personal care article. The method further includes applying and attaching absorbent crotch portion elements to the first and second webs at spaced intervals along the lengths of the respective webs, and bridging the space between the first and second webs, thereby to form a composite web comprising the first and second webs and the respective crotch portions, wherein a given respective crotch portion element has a front segment attached to the first web and a rear segment attached to the second web. Additionally, the method includes bringing the first and second webs of the composite web into facing relationship with each other, including bringing the respective front and rear segments of the respective crotch portion elements generally into facing relationship with each other. The method also includes forming side seam bonds joining the first and second webs to each other at spaced locations along the length of the composite web, thereby to form a composite web sausage having an indefinite length. The method further includes separating discrete lengths of the composite web sausage from the indefinite-length composite web sausage at or proximate respective ones of the side seam bonds, thereby to define respective personal care articles.
In a sixth family of embodiments, the invention comprehends a personal care article comprising a front portion, a rear portion, and a crotch portion extending between the front portion and the rear portion. The front and rear portions each comprise opposing first and second side sections and a central section between the respective side sections, the rear portion and the front portion being attached to each other at respective side sections of the front and rear portions by side seams. The front portion comprises first and second workpieces corresponding to the side sections of the front portion, and an intervening element corresponding to the front central section, the first and second workpieces being releasably attached to the intervening element by releasable fasteners. The releasable fasteners, prior to use by a user, comprise the only attachment attaching the first and second workpieces to the front central section.
In preferred embodiments, the releasable fasteners comprise mechanical fasteners, received in hook receptive material defined at the intervening element.
In some embodiments, the first and second workpieces are attached to the intervening element by fasteners having attachment capability over a substantial portion of an area defining the intervening element.
In some embodiments, the first and second workpieces are attached to the intervening element by first and second attachments defining mechanical fasteners on one of the respective workpieces and/or the intervening element interacting with mechanical loops on the other of the respective workpieces and/or the intervening element.